Eva Braun, who married Nazi leader Adolf Hitler hours before the pair committed suicide in 1945, was of Jewish descent, according to DNA analysis conducted for a TV documentary.
The Dead Famous DNA film - to be screened on Channel 4 on Wednesday - will claim that tests on hair samples said to have come from a monogrammed hairbrush used by Braun, show she was possibly of Jewish ancestry.
A team of scientists examined the hair and found a particular sequence within the DNA, which had been passed down the maternal line - the haplogroup N1b1 - which the channel said was "strongly associated" with Ashkenazi Jews, who make up around 80% of the global Jewish population.
Many Ashkenazi Jews in Germany converted to Catholicism in the 19th century.
Presenter Mark Evans sourced the hair samples, which were originally found by American army intelligence officer Paul Bae at Hitler's mountain retreat.
He said: "This is a thought-provoking outcome - I never dreamt that I would find such a potentially extraordinary and profound result."
The only way to prove beyond doubt that the samples were from Braun would be to take a DNA swab from one of her two surviving female descendants, but both refused.